Process of dyeing sulfur dyes.



UNITED STAT ES PATENT OFFICE.

ADOLF WOSCHER, OF HOCHST-ON-THE-MAIN. GERMANY, ASSIGNOR T FARBWERKE VORM.

MEISTER LUCIUS & BRUNING. OF HOGHST-ON-THE-MAIN, GERMANY, A CORPORATION OF GERMANY.

PROCESS OF DYEING SULFUR DYEB.

Patented Dec. 29, 1908.

Application filed December I, 1907. Serial No. 505,586.

To all whom it me concern:

Be it known at I, AnoLF Woscnnn, colorist, a citizen of the Em ire of Germany, residing at Hochst-on-the-l ain, Germany, have made certain Improvements in Dyeinlg with Sulfurized Dyestuffs, of which the to lowing is a specification.

I have found that it is not essential to avoid the use of alkali sulfid in the dye bath in order to obviate the majority of the drawbacks in dyeing with sulfurized dyestufl's, pl ovided a bisulfite be present in the bath. has by adoptin this ex edient animal fibers may be dyer? with so urized dyestuffs without injury to the material which has been caused hitherto bv the usual alkaline sulfid dye baths. e new process oflers similar advantage in dyeing vegetable fibers.

The invention consists in the practical application of the observation that a dye bath re ared in the usual manner with a sulfurize dyestufi', sodium sulfid and common salt, may be treated with a large quantity of bisulfite without any of the dyestufi being precipitated. The addition neutralizes the injurious influence of the sulfid of the alkali metal to such an extent that excellent dfi'eings can be obtained without detrimenta y afl'ecting the fiber. By this method of working the condition of the dye bath may be compared with that of an indi o vat, only the injurious action of the alkali or alkali sulfid may be neutralized to such a point that wool can be dyed at a comparatively high temperature without danger to the fiber. The dye baths do not become exhausted the operation being similar to that of vat dveing. The baths may be re ared somewhat stronger than usualan in urther workin up, the requisite condition of the dye bath is attained by removing the dyestufi's absorbed by the goods, and by adding an alkali sulfid and isulfite. The success of the dyeing process depends upon the adequate proportion of bisulfite being added so as to neutralize the action of the sodium sulfid. However, too eat an excess of bisulfite must he avoiddd, as it unfavorably influences the dyein In most cases a suitable pro 1'- tion 0 bisulfite has been added when a test portion of the dye bath does not turn red when a. solution of phenolphthalein is added. The best temperature of the bath in dyein 515 wool is generally between'70-80 0., whic ma be raised, however, for dee colors an lowered for light colors. egetable fibers are best dyed at a low temperature. By an immersion of only 1-3 minutes in concentrated baths (compare Examples VI and VII) deep dyes are obtained at higher temperature on wool and silk or half wool and half silk and at lowertemperature on vegetable fibers thus permitting a continuous d eing. The process is also suited for dyeing silk half-silk, leather, furs and paper, materials which could not hitherto e dyed with sulfurized dyestufis owing to the injurious influence of the alkali-sulfid baths. Good results may be obtained with '10 sodium, potassium or ammonium bisulfite. Instead of bisulfites, sulfites may be used in resence of suitable acids or acid salts. If esired, the dyein may be treated subsequently with met '0 salts.

An im ortant result of the invention is that W00 and vegetable fibers may be dyed simultaneously and the temperature of the dye bath may be adjusted so that the dyestufl is taken up more by the vegetable or more by the Wool fiber; the higher the tem erature the more the wool is dyed.

T is process is applicable to various sulfurized dycstuils, good results having been obtained, for instance, with thiogen black, sulfur black, immedial black, thiogen blue, thiogen green, immedial iudone, katigen blue, katigen brown, katigen violet, thiogen dark red, immedial bordeaux, thiogen yellow and others. The fastness of the dyemgs 90 [5 very good.

The following examples illustrate the invention:

Example I: Thedye bath is made up per liter wit 3 grams of thiogen blue B, 4, 5 grams of crystallized sodium sulfid, 4 grams of crystallized sodium bisulfite and 90 grams of crystallized Glaubers salt. The wool is dyed therein for 1 hour at 80 C.; it is then ressed, thorou hl rinsed, acidified if need e, treated in a (lie-extractor and dried.

Exam le II: The dye bath is made at}: per liter wit 20 grams of li uid thiogen lack 132R, 7.5 grams of crystal med sodium sulfid, 7.5 grams of crystallized sodium sulfite, 37.5 cc. of sulfuric acid of 66 Baum specific gravity, 60 grams of Glaubers salt; the wool is dyed in the bath for 1 hour at 80 C., rinsed and dried.

Example III: A solution is prepared 0011- 11c taini per liter 10 grams of li uid thiogen black 2R, 5 grams of crysta zed sodium sulfid and 1020 grams of crystallized sodium bisulfite; leather tanned Wltll chromium is treated in the solution for one-half hour at about 50 C. It is then washed and eased in the usual manner. In such a bat skins, for instance, sheep skins may be dyed in the usual manner by them on suitable boards, care being taken that the hair alone dips into the dye bath. The temperature should be hi her than 50 C. in this case.

Example A dye fluid is repared contsininiiper liter 120 grams of quid thiogen black 60 grams of crystallized sodium snllid and 80 grams of crystallized sodium bisulfite. The ready paper sheet is passed through this fluid on a dyeing machine (for instance, Frenzel's system) then pressed and dried.

Exam le V: The dye bath is made up per liter wit 40 grams of lifiuid tbiogen lack 32R, 20 grams of crysts zed sodium sulfid, 25 grams of crystallized sodium bisulfite, 10 gems of sodium thiosulfate. Silk is dyed erein for about one-half hour at 95 C. pressed, thomugldy rinsed finally soeped while boilingvind acidified if necessary.

Example The dye bath is made up per liter with grams of ii uid thiogen leek B2B, 20 grams of crystal 'zed sodium sulfid, 20 grams of crgtallized sodium bisuliite and 10 grams of laubers salt. Cotton 1s dyed in this bath in the cold within 1-3 minutes a dee black, whereas wool absorbs on! little of t e d estufi.

sample VII: he dye bath is made up r hter with 20-60 grams of liquid thiogen lack M, 20-60 grams of crystallized sodium suliid, about 24-72 ems of crystallined sodm n blsulfite, wool: silk, half wool and half sill; dyed in this bath at 50-90 C. wlthm 1-5 minutes; the goods are then squeezed and washed.

Hevmg now described my invention what I claim is:

The recess herein described of dyeing with en rlzed dyestuffs in an alkali sulfid bath, which conslsts in adding to the dyebeth sulfurous acid in the form of its salts.

Intestnnony, that I claim the foregoing as my invention, I have signed my name in presence of two subscribing witnesses.

ADOLF WOSCHER.

Witnesses J mu Gem, Cm GRUND. 

